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opus/libcelt/celt.c

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/* (C) 2007 Jean-Marc Valin, CSIRO
*/
/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of the Xiph.org Foundation nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "os_support.h"
#include "mdct.h"
#include <math.h>
#include "celt.h"
#include "pitch.h"
#include "fftwrap.h"
#include "bands.h"
#include "modes.h"
#include "probenc.h"
#include "quant_pitch.h"
#include "quant_bands.h"
#include "psy.h"
#define MAX_PERIOD 1024
struct CELTEncoder {
const CELTMode *mode;
int frame_size;
int block_size;
int nb_blocks;
int overlap;
int channels;
int Fs;
ec_byte_buffer buf;
ec_enc enc;
float preemph;
float *preemph_memE;
float *preemph_memD;
mdct_lookup mdct_lookup;
void *fft;
float *window;
float *in_mem;
float *mdct_overlap;
float *out_mem;
float *oldBandE;
};
CELTEncoder *celt_encoder_new(const CELTMode *mode)
{
int i, N, B, C, N4;
N = mode->mdctSize;
B = mode->nbMdctBlocks;
C = mode->nbChannels;
CELTEncoder *st = celt_alloc(sizeof(CELTEncoder));
st->mode = mode;
st->frame_size = B*N;
st->block_size = N;
st->nb_blocks = B;
st->overlap = mode->overlap;
st->Fs = 44100;
N4 = (N-st->overlap)/2;
ec_byte_writeinit(&st->buf);
ec_enc_init(&st->enc,&st->buf);
mdct_init(&st->mdct_lookup, 2*N);
st->fft = spx_fft_init(MAX_PERIOD*C);
st->window = celt_alloc(2*N*sizeof(float));
st->in_mem = celt_alloc(N*C*sizeof(float));
st->mdct_overlap = celt_alloc(N*C*sizeof(float));
st->out_mem = celt_alloc(MAX_PERIOD*C*sizeof(float));
for (i=0;i<2*N;i++)
st->window[i] = 0;
for (i=0;i<st->overlap;i++)
st->window[N4+i] = st->window[2*N-N4-i-1]
= sin(.5*M_PI* sin(.5*M_PI*(i+.5)/st->overlap) * sin(.5*M_PI*(i+.5)/st->overlap));
for (i=0;i<2*N4;i++)
st->window[N-N4+i] = 1;
st->oldBandE = celt_alloc(C*mode->nbEBands*sizeof(float));
st->preemph = 0.8;
st->preemph_memE = celt_alloc(C*sizeof(float));;
st->preemph_memD = celt_alloc(C*sizeof(float));;
return st;
}
void celt_encoder_destroy(CELTEncoder *st)
{
if (st == NULL)
{
celt_warning("NULL passed to celt_encoder_destroy");
return;
}
ec_byte_writeclear(&st->buf);
mdct_clear(&st->mdct_lookup);
spx_fft_destroy(st->fft);
celt_free(st->window);
celt_free(st->in_mem);
celt_free(st->mdct_overlap);
celt_free(st->out_mem);
celt_free(st->oldBandE);
celt_free(st);
}
static void haar1(float *X, int N, int stride)
{
int i, k;
for (k=0;k<stride;k++)
{
for (i=k;i<N*stride;i+=2*stride)
{
float a, b;
a = X[i];
b = X[i+stride];
X[i] = .707107f*(a+b);
X[i+stride] = .707107f*(a-b);
}
}
}
static void time_dct(float *X, int N, int B, int stride)
{
switch (B)
{
case 1:
break;
case 2:
haar1(X, B*N, stride);
break;
default:
celt_warning("time_dct not defined for B > 2");
};
}
static void time_idct(float *X, int N, int B, int stride)
{
switch (B)
{
case 1:
break;
case 2:
haar1(X, B*N, stride);
break;
default:
celt_warning("time_dct not defined for B > 2");
};
}
static void compute_mdcts(mdct_lookup *mdct_lookup, float *window, float *in, float *out, int N, int B, int C)
{
int i, c;
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
float x[2*N];
float tmp[N];
for (j=0;j<2*N;j++)
x[j] = window[j]*in[C*i*N+C*j+c];
mdct_forward(mdct_lookup, x, tmp);
/* Interleaving the sub-frames */
for (j=0;j<N;j++)
out[C*B*j+C*i+c] = tmp[j];
}
}
}
static void compute_inv_mdcts(mdct_lookup *mdct_lookup, float *window, float *X, float *out_mem, float *mdct_overlap, int N, int overlap, int B, int C)
{
int i, c, N4;
N4 = (N-overlap)/2;
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
float x[2*N];
float tmp[N];
/* De-interleaving the sub-frames */
for (j=0;j<N;j++)
tmp[j] = X[C*B*j+C*i+c];
mdct_backward(mdct_lookup, tmp, x);
for (j=0;j<2*N;j++)
x[j] = window[j]*x[j];
for (j=0;j<overlap;j++)
out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] = x[N4+j]+mdct_overlap[C*j+c];
for (j=0;j<2*N4;j++)
out_mem[C*(MAX_PERIOD+(i-B)*N)+C*(j+overlap)+c] = x[j+N4+overlap];
for (j=0;j<overlap;j++)
mdct_overlap[C*j+c] = x[N+N4+j];
}
}
}
int celt_encode(CELTEncoder *st, short *pcm)
{
int i, c, N, B, C, N4;
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
float in[(B+1)*C*N];
float X[B*C*N]; /**< Interleaved signal MDCTs */
float P[B*C*N]; /**< Interleaved pitch MDCTs*/
float mask[B*C*N]; /**< Masking curve */
float bandE[st->mode->nbEBands*C];
float gains[st->mode->nbPBands];
int pitch_index;
N4 = (N-st->overlap)/2;
for (c=0;c<C;c++)
{
for (i=0;i<N4;i++)
in[C*i+c] = 0;
for (i=0;i<st->overlap;i++)
in[C*(i+N4)+c] = st->in_mem[C*i+c];
for (i=0;i<B*N;i++)
{
float tmp = pcm[C*i+c];
in[C*(i+st->overlap+N4)+c] = tmp - st->preemph*st->preemph_memE[c];
st->preemph_memE[c] = tmp;
}
for (i=N*(B+1)-N4;i<N*(B+1);i++)
in[C*i+c] = 0;
for (i=0;i<st->overlap;i++)
st->in_mem[C*i+c] = in[C*(N*(B+1)-N4-st->overlap+i)+c];
}
//for (i=0;i<(B+1)*C*N;i++) printf ("%f(%d) ", in[i], i); printf ("\n");
/* Compute MDCTs */
compute_mdcts(&st->mdct_lookup, st->window, in, X, N, B, C);
compute_mdct_masking(X, mask, B*C*N, st->Fs);
/* Invert and stretch the mask to length of X
For some reason, I get better results by using the sqrt instead,
although there's no valid reason to. Must investigate further */
for (i=0;i<B*C*N;i++)
mask[i] = 1/(.1+mask[i]);
/* Pitch analysis */
for (c=0;c<C;c++)
{
for (i=0;i<N;i++)
{
in[C*i+c] *= st->window[i];
in[C*(B*N+i)+c] *= st->window[N+i];
}
}
find_spectral_pitch(st->fft, in, st->out_mem, MAX_PERIOD, (B+1)*N, C, &pitch_index);
ec_enc_uint(&st->enc, pitch_index, MAX_PERIOD-(B+1)*N);
/* Compute MDCTs of the pitch part */
compute_mdcts(&st->mdct_lookup, st->window, st->out_mem+pitch_index*C, P, N, B, C);
/*int j;
for (j=0;j<B*N;j++)
printf ("%f ", X[j]);
for (j=0;j<B*N;j++)
printf ("%f ", P[j]);
printf ("\n");*/
/* Band normalisation */
compute_band_energies(st->mode, X, bandE);
normalise_bands(st->mode, X, bandE);
//for (i=0;i<st->mode->nbEBands;i++)printf("%f ", bandE[i]);printf("\n");
//for (i=0;i<N*B*C;i++)printf("%f ", X[i]);printf("\n");
/* Normalise the pitch vector as well (discard the energies) */
{
float bandEp[st->mode->nbEBands*st->mode->nbChannels];
compute_band_energies(st->mode, P, bandEp);
normalise_bands(st->mode, P, bandEp);
}
quant_energy(st->mode, bandE, st->oldBandE, &st->enc);
if (C==2)
{
stereo_mix(st->mode, X, bandE, 1);
stereo_mix(st->mode, P, bandE, 1);
//haar1(X, B*N*C, 1);
//haar1(P, B*N*C, 1);
}
/* Simulates intensity stereo */
//for (i=30;i<N*B;i++)
// X[i*C+1] = P[i*C+1] = 0;
/* Get a tiny bit more frequency resolution and prevent unstable energy when quantising */
time_dct(X, N, B, C);
time_dct(P, N, B, C);
/* Pitch prediction */
compute_pitch_gain(st->mode, X, P, gains, bandE);
quant_pitch(gains, st->mode->nbPBands, &st->enc);
pitch_quant_bands(st->mode, X, P, gains);
//for (i=0;i<B*N;i++) printf("%f ",P[i]);printf("\n");
/* Compute residual that we're going to encode */
for (i=0;i<B*C*N;i++)
X[i] -= P[i];
/*float sum=0;
for (i=0;i<B*N;i++)
sum += X[i]*X[i];
printf ("%f\n", sum);*/
/* Residual quantisation */
quant_bands(st->mode, X, P, mask, &st->enc);
time_idct(X, N, B, C);
if (C==2)
//haar1(X, B*N*C, 1);
stereo_mix(st->mode, X, bandE, -1);
renormalise_bands(st->mode, X);
/* Synthesis */
denormalise_bands(st->mode, X, bandE);
CELT_MOVE(st->out_mem, st->out_mem+C*B*N, C*(MAX_PERIOD-B*N));
compute_inv_mdcts(&st->mdct_lookup, st->window, X, st->out_mem, st->mdct_overlap, N, st->overlap, B, C);
/* De-emphasis and put everything back at the right place in the synthesis history */
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
for (j=0;j<N;j++)
{
float tmp = st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] + st->preemph*st->preemph_memD[c];
st->preemph_memD[c] = tmp;
if (tmp > 32767) tmp = 32767;
if (tmp < -32767) tmp = -32767;
pcm[C*i*N+C*j+c] = (short)floor(.5+tmp);
}
}
}
return 0;
}
char *celt_encoder_get_bytes(CELTEncoder *st, int *nbBytes)
{
char *data;
ec_enc_done(&st->enc);
*nbBytes = ec_byte_bytes(&st->buf);
data = ec_byte_get_buffer(&st->buf);
//printf ("%d\n", *nbBytes);
/* Reset the packing for the next encoding */
ec_byte_reset(&st->buf);
ec_enc_init(&st->enc,&st->buf);
return data;
}
/****************************************************************************/
/* */
/* DECODER */
/* */
/****************************************************************************/
struct CELTDecoder {
const CELTMode *mode;
int frame_size;
int block_size;
int nb_blocks;
int overlap;
ec_byte_buffer buf;
ec_enc enc;
float preemph;
float *preemph_memD;
mdct_lookup mdct_lookup;
float *window;
float *mdct_overlap;
float *out_mem;
float *oldBandE;
int last_pitch_index;
};
CELTDecoder *celt_decoder_new(const CELTMode *mode)
{
int i, N, B, C, N4;
N = mode->mdctSize;
B = mode->nbMdctBlocks;
C = mode->nbChannels;
CELTDecoder *st = celt_alloc(sizeof(CELTDecoder));
st->mode = mode;
st->frame_size = B*N;
st->block_size = N;
st->nb_blocks = B;
st->overlap = mode->overlap;
N4 = (N-st->overlap)/2;
mdct_init(&st->mdct_lookup, 2*N);
st->window = celt_alloc(2*N*sizeof(float));
st->mdct_overlap = celt_alloc(N*C*sizeof(float));
st->out_mem = celt_alloc(MAX_PERIOD*C*sizeof(float));
for (i=0;i<2*N;i++)
st->window[i] = 0;
for (i=0;i<st->overlap;i++)
st->window[N4+i] = st->window[2*N-N4-i-1]
= sin(.5*M_PI* sin(.5*M_PI*(i+.5)/st->overlap) * sin(.5*M_PI*(i+.5)/st->overlap));
for (i=0;i<2*N4;i++)
st->window[N-N4+i] = 1;
st->oldBandE = celt_alloc(C*mode->nbEBands*sizeof(float));
st->preemph = 0.8;
st->preemph_memD = celt_alloc(C*sizeof(float));;
st->last_pitch_index = 0;
return st;
}
void celt_decoder_destroy(CELTDecoder *st)
{
if (st == NULL)
{
celt_warning("NULL passed to celt_encoder_destroy");
return;
}
mdct_clear(&st->mdct_lookup);
celt_free(st->window);
celt_free(st->mdct_overlap);
celt_free(st->out_mem);
celt_free(st->oldBandE);
celt_free(st);
}
static void celt_decode_lost(CELTDecoder *st, short *pcm)
{
int i, c, N, B, C;
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
float X[C*B*N]; /**< Interleaved signal MDCTs */
int pitch_index;
pitch_index = st->last_pitch_index;
/* Use the pitch MDCT as the "guessed" signal */
compute_mdcts(&st->mdct_lookup, st->window, st->out_mem+pitch_index*C, X, N, B, C);
CELT_MOVE(st->out_mem, st->out_mem+C*B*N, C*(MAX_PERIOD-B*N));
/* Compute inverse MDCTs */
compute_inv_mdcts(&st->mdct_lookup, st->window, X, st->out_mem, st->mdct_overlap, N, st->overlap, B, C);
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
for (j=0;j<N;j++)
{
float tmp = st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] + st->preemph*st->preemph_memD[c];
st->preemph_memD[c] = tmp;
if (tmp > 32767) tmp = 32767;
if (tmp < -32767) tmp = -32767;
pcm[C*i*N+C*j+c] = (short)floor(.5+tmp);
}
}
}
}
int celt_decode(CELTDecoder *st, char *data, int len, short *pcm)
{
int i, c, N, B, C;
N = st->block_size;
B = st->nb_blocks;
C = st->mode->nbChannels;
float X[C*B*N]; /**< Interleaved signal MDCTs */
float P[C*B*N]; /**< Interleaved pitch MDCTs*/
float bandE[st->mode->nbEBands*C];
float gains[st->mode->nbPBands];
int pitch_index;
ec_dec dec;
ec_byte_buffer buf;
if (data == NULL)
{
celt_decode_lost(st, pcm);
return 0;
}
ec_byte_readinit(&buf,data,len);
ec_dec_init(&dec,&buf);
/* Get the pitch index */
pitch_index = ec_dec_uint(&dec, MAX_PERIOD-(B+1)*N);
st->last_pitch_index = pitch_index;
/* Get band energies */
unquant_energy(st->mode, bandE, st->oldBandE, &dec);
/* Pitch MDCT */
compute_mdcts(&st->mdct_lookup, st->window, st->out_mem+pitch_index*C, P, N, B, C);
{
float bandEp[st->mode->nbEBands];
compute_band_energies(st->mode, P, bandEp);
normalise_bands(st->mode, P, bandEp);
}
if (C==2)
//haar1(P, B*N*C, 1);
stereo_mix(st->mode, P, bandE, 1);
time_dct(P, N, B, C);
/* Get the pitch gains */
unquant_pitch(gains, st->mode->nbPBands, &dec);
/* Apply pitch gains */
pitch_quant_bands(st->mode, X, P, gains);
/* Decode fixed codebook and merge with pitch */
unquant_bands(st->mode, X, P, &dec);
time_idct(X, N, B, C);
if (C==2)
//haar1(X, B*N*C, 1);
stereo_mix(st->mode, X, bandE, -1);
renormalise_bands(st->mode, X);
/* Synthesis */
denormalise_bands(st->mode, X, bandE);
CELT_MOVE(st->out_mem, st->out_mem+C*B*N, C*(MAX_PERIOD-B*N));
/* Compute inverse MDCTs */
compute_inv_mdcts(&st->mdct_lookup, st->window, X, st->out_mem, st->mdct_overlap, N, st->overlap, B, C);
for (c=0;c<C;c++)
{
for (i=0;i<B;i++)
{
int j;
for (j=0;j<N;j++)
{
float tmp = st->out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] + st->preemph*st->preemph_memD[c];
st->preemph_memD[c] = tmp;
if (tmp > 32767) tmp = 32767;
if (tmp < -32767) tmp = -32767;
pcm[C*i*N+C*j+c] = (short)floor(.5+tmp);
}
}
}
return 0;
//printf ("\n");
}
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